Magnetic Targeting Research Articles

Influence of the magnetic field on properties of hot electron emission from ablative plasma produced at laser irradiation of a disc-coil target

Optical generators of strong magnetic fields based on the laser-driven-coil target concept are considered to be useful tools for studies of magnetized plasmas in particular, for the study of implosion of magnetized fusion targets in inertial fusion research and astrophysical applications. This paper presents the results of the research directed at an investigation of the plasma properties in a laser-induced magnetic field. In the experiment carried out on the kilojoule PALS laser facility, a generator of the magnetic field was a disc-coil (DC) target composed of a Cu disk coupled to a single-turn coil irradiated by a 1ω laser beam with an energy of 500 J. The attention was focused on examining the influence of the magnetic field on properties of the hot electron (HE) flux emitted from the front surface of the irradiated target. The three-frame complex interferometry and four-frame x-ray camera combined with the measurements of the HE population and energy using a multi-channel magnetic electron spectrometer and 2D-resolved imaging of the induced Cu Kα line emission were applied to characterize the ablative plasma and the generated particles. Based on the measured angular distributions of the electron energy spectra, 3D simulations have been performed to visualize the effect of the magnetic field on the HE flux and to provide information on space-time distribution of the electron and current density both without and with the presence of an axial magnetic field. The obtained results confirmed the possibility of generating magnetic fields above 5 T using the proposed DC target design as well as the significant impact of these fields on properties of the ablative plasma and the HE emission.

Enhanced Acoustic Droplet Vaporization through the Active Magnetic Accumulation of Drug-Loaded Magnetic Particle-Encapsulated Nanodroplets (MPE-NDs) in Cancer Therapy.

The application of drug-loaded nanodroplets is still limited by their insufficient accumulation owing to the enhanced permeability and retention (EPR) effect failure in cancer therapy. To overcome these limitations, we propose an alternative magnetic particle-encapsulated nanodroplet (MPE-ND) with outstanding biosafety and magnetic targeting by encapsulating fluorinated Fe3O4-SiO2 nanoparticles inside the liquid core of the nanodroplets. Meanwhile, doxorubicin (DOX) can be stably loaded into the shell through both electrostatic and hydrophobic interactions to obtain drug-loaded MPE-NDs. Both in vitro and in vivo experiments have consistently demonstrated that drug-loaded MPE-NDs can significantly increase the local drug concentration and enhance the damage of tumor tissues through acoustic droplet vaporization under a static magnetic field (eADV therapy). Histological examination reveals that eADV therapy efficiently suppresses tumor proliferation by inducing apoptosis, destroying supply vessels, and inhibiting neovascularization. Drug-loaded MPE-NDs can be expected to open a new gateway for ultrasound-triggered drug delivery and cancer treatment.

Dependence of particle and power dissipation on divertor geometry and plasma shaping in DIII-D small-angle-slot divertor

• The compact SAS divertor in DIII-D provides a good testbed for understanding the effects of a tightly closed divertor on particle and power dissipation, and for application to core-edge integration solutions. • A longer outer leg facilitates the achievement of divertor dissipation in the SAS divertor, while a shorter leg leads to higher divertor temperatures and requires higher upstream densities to achieve the same level of divertor detachment. • The divertor conditions strongly depend on the divertor target shaping and Bt direction. • In-slot gas puffing can reduce detachment onset density by about 10% when the outer strike point is placed at the inner slanted surface. • Completed divertor detachment and a high confinement core with normalized energy confinement factor H 98 >1.0 can be simultanesouly achieved with the SAS divertor, demonstrating the benefit of a closed divertor for exploration of core-edge integration. Dedicated experiments in DIII-D find that magnetic shaping and divertor target geometry significantly affect the divertor plasma conditions and divertor detachment process in the small-angle-slot (SAS) divertor. The compact SAS divertor in DIII-D provides a good testbed for understanding the effects of a tightly closed divertor on particle and power dissipation, and for application to core-edge integration solutions. A longer outer leg facilitates the achievement of divertor dissipation in the SAS divertor, while a shorter leg leads to higher electron temperatures near the divertor target plate and requires higher upstream densities to achieve the same level of divertor detachment. In addition, with the ion B × ∇ B drift away from the SAS divertor and the outer strike point (OSP) near the outer corner, the target temperature is lower for a particular upstream density than with the OSP on a slanted or flat surface, leading to lower heat flux even when the particle flux remains similar. In contrast, with the ion B × ∇ B drift into the SAS divertor, a strike point at the inner slanted surface exhibits a lower upstream density to achieve divertor detachment than a strike point either at the outer corner or the outer slanted target. Experimental results and SOLPS-ITER simulations with full drifts suggest the strong interplay between drift flows and the neutral distribution resulted from target shaping. Furthermore, in-slot gas puffing has been shown to achieve global divertor detachment with an onset density about 10% lower than that using main-chamber gas puffing when the outer strike point is placed at the inner slanted surface. Corresponding modelling reveals that the local gas puffing enhances the neutral ionization which potentially facilitates the achievement of divertor dissipation. However, such improvement diminishes when the strike point is at the outer corner, which also indicates the geometric dependence on divertor performance in the SAS divertor. Even with different strike point locations, complete divertor detachment with very low particle and heat fluxes at the divertor targets and a high confinement core with normalized energy confinement factor H 98 >1.0 can be simultanesouly achieved with the SAS divertor with ion B × ∇ B drift into SAS divertor, demonstrating the benefit of a closed divertor for exploration of core-edge integration.

Minimal scanning duration for producing individualized repetitive transcranial magnetic stimulation targets.

This study aimed to determine the minimal scanning duration of functional magnetic resonance imaging (fMRI) for producing individualized repetitive transcranial magnetic stimulation (rTMS) targets that are superior to the group-level targets. This study included 30 healthy subjects and 20 depressive patients with high-sampled fMRI data (> 69min). We computed suboptimal targets by gradually increasing the scanning duration beginning at 6min. The suboptimal target connectivity and spatial distance to the optimal target (based on the full-duration scanning data) were compared to an anatomically fixed target from a group analysis (termed as the group target). These analyses were repeated for healthy subjects and depressive patients, as well as for target masks in the dorsolateral prefrontal cortex (DLPFC) and inferior parietal lobule (IPL). As the scanning duration increased, the suboptimal targets gradually approached the optimal targets in the healthy subjects. Compared with the group targets, the suboptimal targets in the DLPFC showed higher connectivity strength after 10min of data collection and shorter spatial distance after 40min. Similar results were found in major depressive patients. In the IPL, the minimal scanning duration decreased to 6 and 8min for connectivity strength and distance, respectively. These findings provide an important reference for individualized target definition in terms of scanning duration, which may standardize connectivity-based personalized studies. Future research is needed to further validate the therapeutic effects of the approach.

Underwater magnetic field measurement error compensation based on improved mayfly algorithm

This paper investigates the magnetic filed interference problem when the ROV equipped with a three-axis magnetometer measures the magnetic field of underwater magnetic targets within a short range, and a magnetic field compensation method based on an improved mayfly algorithm is proposed to improve the measurement accuracy of underwater magnetic field information. Firstly, a compensation model is established based on the installation error of the three-axis magnetometer and the interference magnetic field of the ROV. Then, in view of the problem that the original mayfly algorithm is easy to fall into local optimal and the convergence accuracy is poor, the Tent chaotic sequence and the Levy flight mutation strategy are introduced to improve the original mayfly algorithm. Finally, a series of magnetic field information is obtained through the three-axis magnetometer, and the original mayfly algorithm, particle swarm algorithm and improved mayfly algorithm are used to estimate the compensation parameters. The experimental results show that the improved mayfly algorithm has obtained faster convergence speed and higher compensation accuracy than others.

The inclination of magnetic dipole effect and nanoscale exchange of heat of the Cross nanofluid

Nanoscale energy exchange and movement of fluid by Lorentz force is the most recent problem that has a strong connection with applied mathematics due to the consumption of energy. Imposing the inclination of Magnetic dipole in the fluid has abundant applications in magnetic drug engineering, astrophysics, sensors, geophysics, cosmology, and targeting. This study is associated with the exchange of energy under the influence of the inclination of Magnetic dipole with cylinder geometry. The Cross nanofluid mathematical model is launched to carry the nanoscale energy exchange with temperature-dependent thermal conductivity. The permeable cylinder geometry along with the different effects is provided during the expanding/contracting cylinder. Whereas Cross fluid helps to investigate the problem in shear thinning/thickening regions. The numerical representations of the problem are provided via the BVP4C scheme.

Efficient delivery of fucoxanthin using metal–polyphenol network-coated magnetic mesoporous silica

Fucoxanthin (FX) is a natural carotenoid pigment that exhibits antitumor activity and is found primarily in brown seaweed. However, its effectiveness as a therapeutic agent varies owing to low bioavailability, poor water solubility, and poor physicochemical stability. The acidic nature of the tumor microenvironment may be utilized to design and construct a targeted magnetic, acid-labile nano-carrier (FX@Fe3O4-mSiO2-TA) with improved FX bioactivity. A nano-drug delivery system composed of magnetic mesoporous silica coated with a tannic acid–iron network (TA/Fe3+) was designed and constructed to improve FX bioactivity based on pH and magnetic targeting in a tumor microenvironment. The external magnetic field guided the carrier to the tumor site.TA/Fe3+ in the outer coating of the carrier was decomposed, resulting in FX release, which was attributed to the low pH of the tumor microenvironment. Drug release was sustained and pH-dependent in vitro, which significantly improved the stability and bioavailability of FX. The simplicity of its preparation and efficacy of the targeted therapeutic suggest the potential of this nano-carrier for application in tumor therapy.

Study of the Structural and Magnetic Properties of a Novel Cola/Lah Nanocomposite Material

A novel nanocomposite consisting of 0.3 cobalt lanthanum nanoferrite/0.7 lanthanum perovskite–hematite nanoparticles (CoLa/LaH) and lanthanum perovskite–hematite nanoparticles (LaH) was synthesized using a simple method. The crystallite size was determined by the X-ray diffraction (XRD) pattern, and the particle size was determined using atomic force microscopy (AFM) to demonstrate that the nano-samples had sizes within the nanoscale range. Fourier transform infrared analysis was utilized to ensure that the nano-samples were formed. By adding CoLa nanoferrite to the LaH nanoparticles, an improvement in magnetic measurements was observed. The saturation magnetization of the CoLa/LaH nanocomposite was 1.1-fold larger than that of LaH. Also, the CoLa/LaH coercivity was 1.7-fold higher than in LaH. Furthermore, the CoLa/LaH nanocomposite displayed a higher operating high frequency of 8.9 GHz, which could be used in an X-band super-high microwave frequency, than the LaH nanoparticles. The LaH nanoparticles, on the other hand, demonstrated a high operating frequency of 8.2 GHz, which could be used in the C-band super-high microwave frequency. No activity was observed for the investigated samples against the tested microorganisms, which was unexpected behavior. Therefore, the investigated nano-samples are interesting for being applied in magnetic targeting and separators, in particular the CoLa/LaH nanocomposite.

Magnetic resonance imaging target fusion biopsy vs. transrectal ultrasound-guided biopsy - A comparative study of ISUP score upgrading risk in the final radical prostatectomy specimen.

The aim of this study was to com-pare the risk of International Society of Urological Pathology (ISUP) score upgrading between magnetic resonance imaging targeted fusion biopsy (MRI-TB) and tran-srectal ultrasound-guided biopsy (TRUS-B) in the final radical prostatectomy (RP) specimen pathological report. This retrospective single center study included 51 patients with prostate cancer (PCa) diagnosed with MRI-TB and 83 patients diagnosed with TRUS-B between October/2019 and July/2021. We compared the rates of ISUP score upgrading between both groups after robotic-assisted radi-cal prostatectomy (RARP) and the specific transition of each ISUP score based on biopsy modality. The rate of ISUP score concordance and downgrading were also assessed. To define the intra and interobserver concordance for each ISUP score in biopsy and RP specimen for each biopsy modality, the Cohen's Kappa coefficient was calculated. ISUP scores and biopsy modal-ity were selected for multivariate analysis and a logistic regres-sion model was built to provide independent risk factors of ISUP score upgrading. The difference of the rate of upgrading between MRI-TB group and TRUS-B group was statistically significant (p = 0.007) with 42.2% of patients of TRUS-B group experiencing an upgrade in their ISUP score while only 19.6% in MRI-TB group. Concordance and downgrading rates did not statistically differ between the two groups. Strength of concordance using Cohen's Kappa coefficient was fair in both groups but higher in MRI-TB group (TRUS-B group k = 0.230; p < 0.001; concordance: 47%vs. MRI/TB group k = 0.438; p < 0.001; concordance: 62.7%). Biopsy modality and ISUP 1 on biopsy were independent predic-tors of ISUP upgrading after RP. MRI-TB is highly accurate with lower risk of PCa upgrading after RP than TRUS-B. Patients with ISUP 1 on biopsy have greater susceptibility to upgrading their ISUP score.

Thrombin‐Loaded Magnetic Microbubbles for the Treatment of Pseudoaneurysms

AbstractThe drive toward minimally invasive surgery has yielded multiple benefits for patients but has also increased the incidence of pseudoaneurysms (PSA). The current standard of care is ultrasound‐guided thrombin injection to coagulate blood in the PSA sac and seal the ruptured vessel. There is, however, a risk of downstream thrombosis if thrombin escapes into the communicating vessel and this limits patient eligibility for thrombin injection. In this study, the feasibility of using magnetic targeting to reduce the risk of distal thrombosis is investigated. Thrombin‐loaded magnetic microbubbles are formulated and injected into tissue‐mimicking phantoms of PSAs with different geometries using either saline or whole (equine) blood. Ultrasound imaging is used to quantify the concentration of bubbles remaining in the sac with and without application of a custom‐built magnetic array. An absorbance‐based assay is also used to quantify the concentration of thrombin escaping from the sac. Magnetic targeting enables a significant increase in thrombin retention in all femoral artery PSA models except one, with up to 97% ± 2.5% of the injected thrombin being retained. It is also confirmed that the enzymatic activity of thrombin is maintained, and that clot formation can be successfully achieved in whole blood.

Magnetoresponsive Functionalized Nanocomposite Aggregation Kinetics and Chain Formation at the Targeted Site during Magnetic Targeting

Drug therapy for vascular disease has been promoted to inhibit angiogenesis in atherosclerotic plaques and prevent restenosis following surgical intervention. This paper investigates the arterial depositions and distribution of PEG-functionalized magnetic nanocomposite clusters (PEG_MNCs) following local delivery in a stented artery model in a uniform magnetic field produced by a regionally positioned external permanent magnet; also, the PEG_MNCs aggregation or chain formation in and around the implanted stent. The central concept is to employ one external permanent magnet system, which produces enough magnetic field to magnetize and guide the magnetic nanoclusters in the stented artery region. At room temperature (25 °C), optical microscopy of the suspension model’s aggregation process was carried out in the external magnetic field. According to the optical microscopy pictures, the PEG_MNC particles form long linear aggregates due to dipolar magnetic interactions when there is an external magnetic field. During magnetic particle targeting, 20 mL of the model suspensions are injected (at a constant flow rate of 39.6 mL/min for the period of 30 s) by the syringe pump in the mean flow (flow velocity is Um = 0.25 m/s, corresponding to the Reynolds number of Re = 232) into the stented artery model. The PEG_MNC clusters are attracted by the magnetic forces (generated by the permanent external magnet) and captured around the stent struts and the bottom artery wall before and inside the implanted stent. The colloidal interaction among the MNC clusters was investigated by calculating the electrostatic repulsion, van der Waals and magnetic dipole-dipole energies. The current work offers essential details about PEG_MNCs aggregation and chain structure development in the presence of an external magnetic field and the process underlying this structure formation.

Modeling and simulation of smart magnetic self-assembled nanomicelle trajectories in an internal thoracic artery flow for breast cancer therapy.

Magnetic drug targeting (MDT) is one of the most modern techniques in cancer therapy for its ability to reduce the side effects of chemotherapy experienced by systemic drug administration. In this study, a comprehensive mathematical model has been developed to predict the drug particle trajectories of anticancer dasatinib magnetic nanomicelles (DAS-MNM) released in an internal thoracic artery (ITA) blood flow for breast cancer therapy using an external magnetic field. Several factors are investigated in regard to the efficiency of MDT through the ITA, including magnetic field strength (MFS), relative magnetic permeability, magnet size, drug particle size, and initial position of drug particle. The drug particle trajectory results confirmed the successful MDT using an external magnetic field with a capture efficiency of more than 90%. This was achieved by employing a wide range of particle sizes of DAS-MNM close to the external magnetic field source at the arterial wall than in other positions. Moreover, the results showed that the number of trapped particles increased with increasing both MFS and drug particle diameter within the target tissue, while the drug particle permeability did not have a considerable effect on the particle retention. In addition, for achieving a successful drug/cargo delivery through the arteries, the magnetic field, the particle size, and the initial release locations should be adjusted simultaneously. The present work offers insights into the critical factors in MDT with a significant impact on breast cancer therapy, tissue engineering, and regenerative medicine. Magnetic drug targeting model of anticancer dasatinib magnetic nanomicelles (DAS-MNM) released in an internal thoracic artery blood flow for breast cancer therapy.

A landmark-based approach to locate symptom-specific transcranial magnetic stimulation targets of depression.

ObjectiveTwo subregions of the dorsolateral prefrontal cortex have been identified as effective repetitive transcranial magnetic stimulation (rTMS) targets for the “anxiosomatic” and “dysphoric” symptoms, respectively. We aimed to develop a convenient approach to locate these targets on the scalp.Materials and methodsIn a discovery experiment, the two personalized targets were precisely identified on 24 subjects using a neuronavigation system. Then, a localized approach was developed based on individual scalp landmarks. This “landmark-based approach” was replicated and validated in an independent cohort (N = 25). Reliability of the approach was tested by calculating the correlation of both the inter-rater and intra-rater results. Validity was tested by comparing the mean distance between the personalized and landmark-based targets to the TMS spatial resolution (i.e., 5 mm). We further conducted a total of 24 sham rTMS sessions to estimate the misplacement between the coil center and target during a 10-min stimulation without neuronavigation.ResultsThe parameters of the “landmark-based approach” in the discovery experiment were replicated well in an independent cohort. Using discovery parameters, we successfully identified the symptom-specific targets in the independent cohort. Specifically, the mean distance between the personalized and landmark-based targets on the cortex was not significantly larger than 5 mm. However, the personalized and landmark-based targets distance exceeded 5 mm in more than 50% of subjects. During the 10-min sham rTMS session, the average coil misplacement was significantly larger than 5 mm.ConclusionThe “landmark-based approach” can conveniently and reliably locate the two symptom-specific targets at group level. However, the accuracy was highly varied at individual level and further improvement is needed.

Reduced Steering Performance in Magnetic Drug Targeting Induced by Shielding Arising from Accumulation of Particles

Abstract Magnetic Drug Targeting is a new approach in cancer therapy, where magnetic nanoparticles are used as carriers for cancer drugs. Commonly, external magnets are employed for steering the particles inside the blood vessels towards a desired direction. However, an unwanted side effect of the steering is the accumulation of the particles underneath the steering magnet. Many researchers address the number of accumulated particles, but, to the best of the authors’ knowledge, the retroaction of the accumulation profile on the generated magnetic field and, therefore, on the magnetic steering force, has not been investigated so far. Thus, in the proposed study, the influence of the accumulation profile on the magnetic force was numerically investigated. Therefore, a 2D model of a blood vessel with particles assumed as an accumulation profile and a nearby magnet was examined. Moreover, the length, thickness, and effective susceptibility of the approximated accumulation profile and the magnet size were varied. The results reveal that the field distribution is significantly affected, especially for high effective susceptibilities. The initially applied profile amplified the magnetic force; however, when the profile accumulated, it reduced the force up to 50 %. Overall, the results reveal that the retroaction of the particle distribution on the magnetic field must be considered in a simulation model.

Investigation of a tunnel magnetoresistance based vector magnetometer for magnetic anomaly detection

The development of high-performance and miniaturized magnetometers is important for small-scale target magnetic anomaly detection. In this work, a miniaturized three-axis vector magnetometer based on the tunnel magnetoresistance (TMR) technique is investigated for magnetic anomaly detection. First, the miniaturized three-axis TMR vector magnetometer is constructed, and then, the limit of detection tests and the magnetic anomaly detection tests are performed. The indoor experimental results show that the proposed magnetometer can capture the magnetic anomalies higher than 3.9 nT, with the low-frequency equivalent magnetic noise of 46.89 pT/√Hz@1Hz. The outdoor experimental results show that the proposed magnetometer can effectively detect small-scale magnetic targets such as hammers at a distance of about 1.5 m. With the advantages of small size, low power consumption, and high magnetic measurement sensitivity, the TMR magnetometer has great application prospects for long-term magnetic anomaly monitoring, high-density magnetic imaging, and other fields.

Geophysical surveying for the detection of ferrous-based objects: possibilities for depth estimative combining analytic signal and vertical integral of the anomalous magnetic field

The detection of buried clandestine objects challenges forensic and archeologic search group teams on varying terrains, and variable scales of research. Therefore, the study of controlled buried objects is useful for trainings in geophysical acquisition and processing. In this study, we applied ground survey data for testing the magnetic method at controlled geophysical sites for the location of ordinary objects and firearms. We used data filtering techniques in order to facilitate the location of magnetic targets. Also, we experienced the 3D inversion of analytic signal of the vertically integrated magnetic field (ASVI), for the location of targets in depth. As a result, the study determined the location of four magnetic targets, and a three-dimensional view was constructed from the estimated magnetic susceptibility. We concluded that modeling transformed magnetic data is an affordable technique for application in near-surface investigations. Also, this experiment exemplifies the relevance of magnetic methods for location of excavation sites on the basis of geophysical methods.

Construction of magnetic drug delivery system and its potential application in tumor theranostics

Magnetic nanoparticles(NPs) are characterized by a rich variety of properties. Because of their excellent physical and chemical properties, they have come to the fore in biomedicine and other fields. The magnetic NPs were extensively studied in magnetic separation of cells, targeted drug delivery, tumor hyperthermia, chemo-photothermal therapy, magnetic resonance imaging (MRI) and other biomedical fields. Magnetic NPs are increasingly used in magnetic resonance imaging (MRI) based on their inherent magnetic targeting, superparamagnetic enzyme-like catalytic properties and nanoscale size. Poly(lactic-co-glycolic acid) (PLGA) is a promising biodegradable material approved by FDA and EU for drug delivery. Currently, PLGA-based magnetic nano-drug delivery systems have attracted the attention of researchers. Herein, we achieved the effective encapsulation of sized-controlled polyethylene glycol-3,4-dihydroxy benzyl-amine-coated superparamagnetic iron oxide nanoparticles (SPIO NPs) and euphorbiasteroid into PLGA nanospheres via a modified multiple emulsion solvent evaporation method (W1/O2/W2). NPs with narrow size distribution and acceptable magnetic properties were developed that are very useful for applications involving cancer therapy and MRI. Furthermore, SPIO-PLGA NPs enhanced the MRI T2 relaxation properties of tumor sites.The prepared SPIO NPs and magnetic PLGA nanospheres can be promising magnetic drug delivery systems for tumor theranostics. This study has successfully constructed a tumor-targeting and magnetic-targeting smart nanocarrier with enhanced permeability and retention, multimodal anti-cancer therapeutics and biodegradability, which could be a hopeful candidate for anti-tumor therapy in the future.

A new nanohybrid with BODIPY and Fe3O4 modified graphdiyne oxide in theranostic

Graphdiyne (GDY) is a new 2D carbon material different from graphene, and its ideal drug carrying and photothermal therapy efficacy had been noticed recently. Graphdiyne-oxide (GDYO), which few phototherapy researches had been reported, has more oxygen functional groups than GDY. Metal-organic framework materials Fe3O4@UiO-66-NH2 (FU) can covalently connect to GDYO layers and obtain covalent-organic framework-like structures FUGYO. FU enlarged interlamellar space of GDYO, which avoided the aggregation of FUGYO multiple layers. At the same time, more acetylenic bonds and hydrophilic group were exposed, which brings out advantages like stability, hydrophily, high drug-loading, as well as magnetic targeting and better magnetic resonance imaging efficacy. To promote cancer treatment effect and water solubility, we loaded chemotherapy drug doxorubicin (DOX) in FUGYO, then encapsulated FUGYO/DOX in phosphatidylcholine and fluorescent organic polymer BODIPY-PEG (BP) to integrate image-guided and synergistic therapy in one nanoparticle (BPFG/DOX). Due to the unique structure of BPFG/DOX, the π–π interaction between GDYO and BP improved photodynamic therapy efficiency. About 10 μg ml−1 BPFG/DOX have nearly 90% cell lethality to MCF-7 (human breast cancer cell line) cells with laser irradiation. In vivo, BPFG/DOX possessed ideal magnetic targeting and effectively inhibited tumor growth in 6 d. In conclusion, BPFG/DOX not only acts as an excellent tumor theranostic agent but also provides a scheme for applying GDYO in the biomedical region.

Improvement of the bladder perfusion curative effect through tight junction protein degradation induced by magnetic temperature-sensitive hydrogels.

Postoperative intravesical instillation of chemotherapy is a routine procedure for non-muscular invasive bladder cancer (NMIBC). However, traditional bladder perfusion methods have insufficient exposure time, resulting in unsatisfactory therapeutic effects. In the present study, a chitosan (CS)-based in situ forming depot (ISFD) delivery system, including Fe3O4 magnetic nanoparticles (Fe3O4-MNP), CS, and β-glycerophosphate (GP) as main components, was synthesized. Pirarubicin (THP), as a chemotherapeutic drug, was loaded into the new system. Results showed that our carrier system (Fe3O4-THP-CS/GP) was converted into gel and attached to the bladder wall, possessing loose network structures with magnetic targeting and sustained release properties. Moreover, its retention time in bladder was more than 72 h accompanied by a suitable expansion rate and good degradation characteristics. The antitumor activities of Fe3O4-THP-CS/GP were more effective both in vitro and in vivo than the free THP solution. In the study of its mechanism, results showed that Fe3O4-THP-CS/GP suppressed the expression of occludin (OCLN) and affected tight junctions (TJ) between urothelial cells to promote THP absorption.

Superparamagnetic Iron Oxide Nanoparticles for Targeted Cell Seeding: Magnetic Patterning and Magnetic 3D Cell Culture

AbstractIn regenerative medicine, noncontact manipulation of cells enables new possibilities for tissue engineering. Due to their physicochemical properties, superparamagnetic iron oxide nanoparticles (SPIONs) are used in biomedicine for various applications, e.g., as drug transporters, contrast agents or to make cells maneuverable by magnetic forces. SPIONs attached to and/or taken up by cells enable their magnetic targeting for adoptive immune therapies or tissue engineering. Remote control of different “magnetized” cell types can be used to construct multilayered tissues without the need for a scaffold structure. Here, the suitability of SPIONs with various coatings, such as polyacrylic acid‐co‐maleic acid (PAM), lauric acid (LA), lauric acid‐human serum albumin (HSA), and citrate to magnetize cells is compared with the commercially available NanoShuttle‐PL, designed for use in magnetic 3D cell cultures. Depending on the amount of cellular labeling, magnetic control is more or less effective. In particular, PAM‐ and citrate‐coated SPIONs achieve good cellular loading and provide magnetic controllability of cells. In 2D cell culture, the magnetic cargo allows the patterned culture of cells. In 3D, SPIONs enable and accelerate spheroid formation as well as micropatterning using unloaded and loaded cells in parallel.